Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA147717 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR349806.fastq.gz | Fastqsanger.gz | |||
| SRR349807.fastq.gz | Fastqsanger.gz | |||
| SRR349808.fastq.gz | Fastqsanger.gz | |||
| SRR349809.fastq.gz | Fastqsanger.gz | |||
| SRR349810.fastq.gz | Fastqsanger.gz |
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Project description:Approximately half of purified mammalian RNA polymerase II (Pol II) is associated with a tightly interacting sub-stoichiometric subunit called Gdown1, encoded by the POLR2M gene. Previous in vitro and structural studies have established that Gdown1 potently inhibits transcription initiation through competitive interactions with general transcription factors and blocks the Pol II termination activity of transcription termination factor 2 (TTF2). However, the biological functions of Gdown1 remain poorly understood. Here, we utilized genetic, microscopic, and multi-omics approaches to functionally characterize Gdown1 in multiple human cell lines. Remarkably, acute depletion of Gdown1 led to minimal direct effects on gene expression and transcription. We show that Gdown1 resides predominantly in the cytoplasm of interphase cells, shuttles between the cytoplasm and nucleus, and is directly regulated by nuclear export. Gdown1 enters the nucleus at the onset of mitosis prior to complete breakdown of the nuclear envelope, whereupon association with Pol II becomes possible. Consistently, genetic ablation of Gdown1 is associated with partial de-repression of mitotic transcription, and Gdown1 KO cells present with a growth defect and evidence of aberrant mitoses coupled to p53 pathway activation. Evidence is presented demonstrating that Gdown1 association with Pol II elongation complexes in vitro modulates the combined functions of purified productive elongation factors PAF1C, RTF1, SPT6, DSIF, and P-TEFb. Collectively, our findings support a model wherein the Pol II-regulatory function of Gdown1 occurs during mitosis and is required for genome integrity.
2022-01-03 | GSE186133 | GEO
Project description:Most human genes are loaded with promoter proximally paused RNA polymerase II (RNAP II) molecules that are poised for release into productive elongation by P-TEFb. Gdown1, a protein that renders RNAP II responsive to mediator, is involved in RNAP II elongation control. During in vitro transcription assays Gdown1 specifically blocked elongation stimulation by TFIIF, inhibited the termination activity of TTF2, and influenced pausing factors NELF and DSIF, but did not affect the function of TFIIS or the mRNA capping enzyme. Without P-TEFb, Gdown1 led to the production of stably paused polymerases in the presence of nuclear extract. ChIP-Seq data demonstrated that Gdown1 mapped over essentially all poised polymerases across the human genome. Gdown1 increases the stability of poised polymerases while maintaining their responsiveness to P-TEFb, and mediator overcomes a Gdown1-mediated block of initiation by allowing TFIIF function. 7 ChIP-Seq data for Pol II and Gdown1 in human HeLa cell. See associated publication.
2012-01-13 | E-GEOD-32442 | biostudies-arrayexpress
Project description:Most human genes are loaded with promoter proximally paused RNA polymerase II (RNAP II) molecules that are poised for release into productive elongation by P-TEFb. Gdown1, a protein that renders RNAP II responsive to mediator, is involved in RNAP II elongation control. During in vitro transcription assays Gdown1 specifically blocked elongation stimulation by TFIIF, inhibited the termination activity of TTF2, and influenced pausing factors NELF and DSIF, but did not affect the function of TFIIS or the mRNA capping enzyme. Without P-TEFb, Gdown1 led to the production of stably paused polymerases in the presence of nuclear extract. ChIP-Seq data demonstrated that Gdown1 mapped over essentially all poised polymerases across the human genome. Gdown1 increases the stability of poised polymerases while maintaining their responsiveness to P-TEFb, and mediator overcomes a Gdown1-mediated block of initiation by allowing TFIIF function.
2012-02-21 | GSE35882 | GEO
Project description:Most human genes are loaded with promoter proximally paused RNA polymerase II (RNAP II) molecules that are poised for release into productive elongation by P-TEFb. Gdown1, a protein that renders RNAP II responsive to mediator, is involved in RNAP II elongation control. During in vitro transcription assays Gdown1 specifically blocked elongation stimulation by TFIIF, inhibited the termination activity of TTF2, and influenced pausing factors NELF and DSIF, but did not affect the function of TFIIS or the mRNA capping enzyme. Without P-TEFb, Gdown1 led to the production of stably paused polymerases in the presence of nuclear extract. ChIP-Seq data demonstrated that Gdown1 mapped over essentially all poised polymerases across the human genome. Gdown1 increases the stability of poised polymerases while maintaining their responsiveness to P-TEFb, and mediator overcomes a Gdown1-mediated block of initiation by allowing TFIIF function.
2012-01-13 | GSE32442 | GEO
Project description:Most human genes are loaded with promoter proximally paused RNA polymerase II (RNAP II) molecules that are poised for release into productive elongation by P-TEFb. Gdown1, a protein that renders RNAP II responsive to mediator, is involved in RNAP II elongation control. During in vitro transcription assays Gdown1 specifically blocked elongation stimulation by TFIIF, inhibited the termination activity of TTF2, and influenced pausing factors NELF and DSIF, but did not affect the function of TFIIS or the mRNA capping enzyme. Without P-TEFb, Gdown1 led to the production of stably paused polymerases in the presence of nuclear extract. ChIP-Seq data demonstrated that Gdown1 mapped over essentially all poised polymerases across the human genome. Gdown1 increases the stability of poised polymerases while maintaining their responsiveness to P-TEFb, and mediator overcomes a Gdown1-mediated block of initiation by allowing TFIIF function. 1 whole cell extract sample in human HeLa cell. See associated publication.
2012-02-21 | E-GEOD-35882 | biostudies-arrayexpress
Project description:Pol II(G) is a novel form of RNA polymerase II that contains a tightly associated Gdown1 polypeptide. Whereas Pol II suffices for robust activator-dependent transcription in the absence of Mediator, Pol II(G) is highly dependent upon Mediator in a biochemically defined in vitro system. However, the mechanism(s) whereby Gdown1 alters the coactivator-dependence of Pol II is unknown. Here we show that Gdown1 competes with TFIIF for binding to the RPB1 and RPB5 subunits of Pol II in vitro, resulting in inhibition of a critical function of TFIIF in facilitating PIC assembly. The apparent inability of Pol II(G) to associate with TFIIF suggests that Gdown1 must be removed from Pol II for transcription initiation. However, Mediator can actually help Pol II(G) bind to the promoter prior to subsequent Mediator functions. Complementary cell-based analyses reveal that Pol II(G) is recruited to promoter regions of subsets of actively transcribed genes, where Pol II(G) appears to modulate transcription. Our findings indicate that differential regulation of subsets of genes by Pol II and Pol II(G) occurs through the regulation of TFIIF and consequent alterations in Mediator requirements. Genome-wide localization of PolII and Gdown1 in human IMR90 fibroblast cells using ChIP-seq
2012-01-13 | E-GEOD-33128 | biostudies-arrayexpress
Project description:Approximately half of purified mammalian RNA polymerase II (Pol II) is associated with a tightly interacting sub-stoichiometric subunit, Gdown1. Previous studies have established that Gdown1 inhibits transcription initiation through competitive interactions with general transcription factors and blocks the Pol II termination activity of transcription termination factor 2 (TTF2). However, the biological functions of Gdown1 remain poorly understood. Here, we utilized genetic, microscopic, and multi-omics approaches to functionally characterize Gdown1 in three human cell lines. Acute depletion of Gdown1 caused minimal direct effects on transcription. We show that Gdown1 resides predominantly in the cytoplasm of interphase cells, shuttles between the cytoplasm and nucleus, and is regulated by nuclear export. Gdown1 enters the nucleus at the onset of mitosis. Consistently, genetic ablation of Gdown1 is associated with partial de-repression of mitotic transcription, and Gdown1 KO cells present with evidence of aberrant mitoses coupled to p53 pathway activation. Evidence is presented demonstrating that Gdown1 modulates the combined functions of purified productive elongation factors PAF1C, RTF1, SPT6, DSIF, and P-TEFb in vitro. Collectively, our findings support a model wherein the Pol II-regulatory function of Gdown1 occurs during mitosis and is required for stably maintaining a pattern of gene expression across cell divisions. To characterize potential interactors of Gdown1 in the cytoplasm, an eGFP-TEV-Gdown1 HAP1 cell line was developed. Cytosolic extracts were prepared, GFP-Trap Agarose (Chromotek) was utilized to pull down Gdown1 and associated factors, and associated proteins were characterized by LC-MS/MS.
2022-02-14 | PXD029425 | Pride
Project description:Pol II(G) is a novel form of RNA polymerase II that contains a tightly associated Gdown1 polypeptide. Whereas Pol II suffices for robust activator-dependent transcription in the absence of Mediator, Pol II(G) is highly dependent upon Mediator in a biochemically defined in vitro system. However, the mechanism(s) whereby Gdown1 alters the coactivator-dependence of Pol II is unknown. Here we show that Gdown1 competes with TFIIF for binding to the RPB1 and RPB5 subunits of Pol II in vitro, resulting in inhibition of a critical function of TFIIF in facilitating PIC assembly. The apparent inability of Pol II(G) to associate with TFIIF suggests that Gdown1 must be removed from Pol II for transcription initiation. However, Mediator can actually help Pol II(G) bind to the promoter prior to subsequent Mediator functions. Complementary cell-based analyses reveal that Pol II(G) is recruited to promoter regions of subsets of actively transcribed genes, where Pol II(G) appears to modulate transcription. Our findings indicate that differential regulation of subsets of genes by Pol II and Pol II(G) occurs through the regulation of TFIIF and consequent alterations in Mediator requirements.
2012-01-13 | GSE33128 | GEO
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes
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Project description:We analyzed the breadth and functional relationships of RNA Polymerase II pausing across many human and mouse cell types to understand what roles RNA Polymerase II pausing plays in gene regulation. We identified a novel association of H2A.Z at the TSS of increasingly paused genes. We knocked down H2A.Z to test whether H2A.Z positively or negatively affects RNA Polymerase II pausing to find that pausing globally increased upon knockdown.
2016-04-28 | GSE60872 | GEO